Expanding tool



Aug. 21, 1945. J. J, TwARDowsK'l 2,383,028

EXPANDING TOOL Filed oct. 25, 1943 INVENTOR. 'jm/Ay. Magnan/@ef Patented ug. 21, 1945 asziaozfA p u EXPANDING 'rooL "l John J. Twaaowski, Phuaaelpniagai N Y Application October 25, 1943, Serial No. 507,559 7 4 claims. (cia3- 159) This invention relates to expanding tools of the type commonly employedas gauges or tram- `mels and is concerned primarily with the provision of a tool having novel features which afford advantages in the use of the tool.

An important object is the provision of an expanding tool of the character aforesaid which is susceptibleA of use with a high degree lof accuracyito perform.. various types of work, and which is easily manipulated -and adjusted to `suit the conditions of the worin` i Accordingly, a further object is the provision of an expanding tool of thetype noted in which each of a pair of slides carries a sribing point with the slides mounted for relativemovement on a slide barand actuatingscrew assembly. i

' An` important detailed object of the invention is the pro-Vision of means for locking the "slides in an adjusted position.`

A somewhat more detailed object of the iri-` vention is the `provisionbfan expanding tool of `the character aforesaid in which the scribing points themselves are replaceable, and the stmotural elements which immediately carry .the scribing points are interchangeable.

Various other more detailed objects and advantages of the invention, such as arise in carrying out the above-noted ideas in a practical embodiment, will in part become apparent and in part be hereinafter stated as a. description of the invention proceeds.

The invention, therefore, comprises an expanding tool intended to be used as a gauge or trammel, and which consists of a pair of relatively movable slides that are mounted on a slide bar and actuating screw assembly with each slide carrying a scribing point. `Means is provided for locking the slides in an adjusted position.

For a full and more complete understanding of the invention, reference may be had to the following description and' accompanying drawing, wherein:

Figure 1 is a perspective of an expanding tool made in accordance with the precepts of this invention;

Figure 2 is a detail taken as a top plan with parts broken away and shown in section; and

Figure 3 is an elevational showing of the structure for mounting one of the scribing points, the

Vparts being shown in exploded relation.

Referring now to the drawing, wherein like reference characters denote corresponding parts, and rst more particularly to Figure 1, a pair of slide bars are designated I and I I. Between the slide bars' I0 and II is an actuating `screw lz having oppsiteiy threaded portions. much the same as AVa Vturbuckle` screw.,` f 1 Referring for thefmoment more particularly to Figure 2`,"itwill befnoted that each of lthe 'slidel bars `I0 and IIgis'iormed with a portion of reduced diameter isubstantially midway thereof. These portionsfo rre'diic'zed diameter Aare identihed' at I3 and |`4."""Th'e` actuating screw I2 has a similar portion I5 of reduceddiarneter. For a short distance on each side Vo'ii'thr'e portion I5, the screwmember I;2 is free" bffthreads'providing thefsmoothwp'arts I`6,"` f' 1 A clamping assembly islreferred to in its entirety by the referencecharacter C and i comprises complementalrhalves I1 and IB, each of which is providedwithlrecesses whichreceive the portionsi3`, I 4 and] 5 of the slide bars and screw; After the elements I'Iand I8 are assembled on the slide barsand screw, the "assembled relation may Ibelmore or less permanently established by fastening these halvesf I1 andal together in any preferred manner such as by the screws rep- `resented at I9.

Carried by the actuating screw I2 on opposite sides of the clamp C are locking nuts 20 and 2|. These nuts are of duplicate construction, and it will be noted from Figure 2 that each is countersunk to accommodate the smooth part I6 of the screw. The purpose of these locking nuts 20 and 2I will later be described.

The slides 22 and 23 are mounted for movement along the slide bars, and, inasmuch as these slides, together with the mechanism `carried thereby, are of duplicate construction, only one of them needs here be 'described for the purpose of this specication. Thus, it is noted that the slide 22 has a central threaded opening 24 through which is threaded the actuating screw I2. On each side of the central opening 24 are smooth bores 25 and 26 through which the slides I0 and II pass.

Referring now more particularly to Figure 3, a i

carrier for a scribing point is shown at 21. The member 21 is formed with wrench engaging flats 28, and at one end carries a threaded plug 29 which is screwed into a complemental recess in the slide 22. At the opposite end, the carrier 21 is formed with a threaded recess 30 which receives the threaded portion 3| of a scribing point 32. A lock nut, shown at 33, may be employed to ,insure that the scribing point 32 remains in position.

When the slides 22 and 23 are to be expanded or contracted, the lock nuts 20 and 2I are first loosened so that they are retracted a slight distance from the centra1 clamp C. The actuating screw I2 is now rotated, and, due to the threaded relationv at the openings 24, the slides 22 and 23 are moved `in a direction corresponding to the direction of rotation of the screw I2. Once the required, distance between the slides 22 and 23 is accurately established, the lock nuts 20 and 2| may be tightened against the clamp C tc positively maintain the adjusted position.

The upper and lower faces of the clampy halves, I'I and I8? respectively, may be provided with center lines as shown at 34 and 35, which will prove of aid for many uses of the tool. It is noted that the scribng point carriers 21 on the slides 22 and 23 are interchangeable and may be, re placed as occasion demands. Likewise, the; scrib ing points 32 may be removed for sharpening or replacement as may be required..

Each of the carriers 2'I may also be formed with a threaded opening 36 which will prove of aid in some uses of the tool in layoutwork.

While a preferredspeeic. embodiment oi the invention is hereinbeforesetyforth, itis. tov be clearly understood that the invention is not to be limited to the exact constructions illustrated and described, because-various modications of these details: may be: provided inputting the invention into practice, within the purview-of the appended claims.

What; is claimedisziv v l. In expanding. tool', ot the character described, an actuating screw, `a pair of slide `bars arranged on opposite. sid'esof said screw,V a central clamp assembled on said slide bars andi screw, means to hold saidl central cla-mp against longitudinal movement. relative to said slide bars and screw, a pair of slides. carried'bysaid' slide bars and screw on opposite sidesof said; central clamp, and. a. scribing point carried by each of said slides.

2., In an expanding tool of the character described, a pairof slide bars withan actuating lift) screw therebetween and maintained in this position by a clamping assembly, said clamping assembly consisting of complemental elements formed with recesses receiving reduced portions of said slide bars and screw, together with means for maintaining the complemental elements in tightly clamped position, a pair of slides arranged on opposite sides of said clamping assembly each slide being formed with a threaded opening into which, is threaded the actuating screw, and a pair of smooth bores receiving the slide bars, and a scribing point carried by' each of said slides.

3. In an expanding tool of the character described, a pair of slide bars with an actuating screwA therebetween and maintained in this position by a clamping assembly, said clamping assembly consisting of complemental elements formed with. recesses receiving reduced portions of said. slide bars and screw, together with means forl maintaining the complemental elements in tightly clamped position,l a pair of slides arranged on, opposite sides of ysaid clamping assemblyl each slide being formedwi-tha threaded opening into which. is threaded the actuating screw and a pair of smooth bores receiving the` slide, bars, each of said slides being formed with a threaded socket, a carrier screwed into said. socket, and a scribing point. detachably carried by said carrier.

4. Inanexpand-ing tool of thev character de,- scribed ay pair of slide bars with an actuating screw therebetween and, maintained in this positionfby a clamping assemblyysaid clampingv assembly consisting of complemental elements formedwith recesses. receiving reduced portions of said. slide bars and screw, together with means for maintaining the complemental elements in tightly` clamped position, and a pair of lock nuts carried by said actuating screw and arranged on opposite sides o'f said clamping assembly.

JOI-IN J. TWARDOWSKI. 

